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In: Statistics and Probability

Batteries produced by a manufacturing company have had a life expectancy of 135 hours. Because of...

Batteries produced by a manufacturing company have had a life expectancy of 135 hours. Because of an improved production process, the company believes that there has been anincreasein the life expectancy of its batteries. A sample of 42 batteries showed an average life of 140 hours. From past information, the standard deviation of the population is known to be 24 hours.

a.Start by writing down the null and alternative hypotheses.

b.Next, calculatethe relevant test statistic.

c.What conclusion can be made at the .10 level of significance? Make sure to interpret in words.

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Expert Solution

orchestra answered 2 years ago
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